The R43 Phase of this project aims to develop and demonstrate a capillary isoelectric focusing-based multidimensional separation platform, capable of providing significant analyte concentration and extremely high resolving power for handling complex proteome mixtures prior to mass spectrometry analysis. Our initial results have proven the potential of the proposed proteome instrumentation technology for increasing proteome coverage, particularly toward sensitive detection of low abundance proteins. The results of the R43 Phase studies will afford further optimization of the proposed proteome instrumentation technology while providing information necessary to guide the implementation, design, and completion of an automated, high throughput, robust, sensitive, and ultrahigh resolution proteome instrument in the R44 Phase studies. The resulting proteome instrument will be at least two to three orders of magnitude more sensitive than the current 2-D PAGE and non-gel based proteome techniques, allowing ultrasensitive proteomic studies of small cell population and limited tissue samples. Additionally, the targeted overall peak capacity and dynamic range of the proposed proteome instrumentation technology range from several times to one-two orders of magnitude greater than those reported in the literature using current proteome separation techniques. [unreadable] [unreadable]